Vanessa Fraser was the first BTC runner to hint that something was up (likely a 5k):
https://www.instagram.com/p/CIMCI7Jn1n7/
Then, today, Gwen Jorgensen confirmed:
https://www.instagram.com/p/CIMCI7Jn1n7/
And -- surprised no one has commented on this -- Centro is running the 13:30 5k race:
8:45 PM (sub 13:30)
Darius Terry
Jaret Carpenter
Fearghai Curtain
...
Matt Centrowitz
Obsa Ali
Cole Hocker